Spacer insertion instrument

ABSTRACT

A percutaneous and minimally invasive instrument for inserting an interspinous process spacer into a patient is disclosed. The insertion instrument includes a first assembly connected to a handle assembly. The first assembly includes an inner shaft located inside an outer shaft; the inner and outer shafts being configured for relative translational motion with respect to each other to thereby deflect at least one prong formed on one of the inner or outer shafts wherein such deflection causes engagement with a juxtapositioned interspinous spacer. The instrument further includes a driving tool configured for removable insertion into a proximal end of a passageway of the instrument. The driving tool has a distal spacer engaging portion configured to engage that part of the spacer requiring activation for deployment of the spacer from at least one undeployed configuration to at least one deployed configuration and vice versa.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application Ser. No. 61/008,418 entitled “Spacer insertioninstrument” filed on Dec. 19, 2007 which is incorporated herein byreference in its entirety. This application also claims priority to andis a continuation-in-part of U.S. patent application Ser. No. 12/205,511entitled “Interspinous spacer” filed on Sep. 5, 2008, now U.S. Pat. No.8,123,782, which is a non-provisional of U.S. Provisional PatentApplication Ser. No. 60/967,805 entitled “Interspinous spacer” filed onSep. 7, 2007 and a continuation-in-part of U.S. patent application Ser.No. 12/220,427 entitled “Interspinous spacer” filed on Jul. 24, 2008,now U.S. Pat. No. 8,277,488 which is a non-provisional of U.S.Provisional Patent Application Ser. No. 60/961,741 entitled“Interspinous spacer” filed on Jul. 24, 2007 and is acontinuation-in-part of U.S. patent application Ser. No. 12/217,662entitled “Interspinous spacer” filed on Jul. 8, 2008, now U.S. Pat. No.8,273,108, which is a non-provisional of U.S. Provisional PatentApplication No. 60/958,876 entitled “Interspinous spacer” filed on Jul.9, 2007 and a continuation-in-part of U.S. patent application Ser. No.12/148,104 entitled “Interspinous spacer” filed on Apr. 16, 2008 nowU.S. Pat. No. 8,292,922 which is a non-provisional of U.S. ProvisionalPatent Application Ser. No. 60/923,971 entitled “Interspinous spacer”filed on Apr. 17, 2007 and U.S. Provisional Patent Application Ser. No.60/923,841 entitled “Spacer insertion instrument” filed on Apr. 16,2007, all of which are hereby incorporated by reference in theirentireties. This application is also a continuation-in-part of U.S.patent application Ser. No. 11/593,995 entitled “Systems and methods forposterior dynamic stabilization of the spine” filed on Nov. 7, 2006, nowU.S. Pat. No. 8,425,559 and a continuation-in-part of U.S. patentapplication Ser. No. 11/582,874 entitled “Minimally invasive tooling fordelivery of interspinous spacer” filed on Oct. 18, 2006, now U.S. Pat.No. 8,128,662 and a continuation-in-part of U.S. patent application Ser.No. 11/314,712 entitled “Systems and methods for posterior dynamicstabilization of the spine” filed on Dec. 20, 2005, now U.S. Pat. No.8,152,837 and a continuation-in-part of U.S. patent application Ser. No.11/190,496 entitled “Systems and methods for posterior dynamicstabilization of the spine” filed on Jul. 26, 2005, now U.S. Pat. No.8,409,282 and a continuation-in-part of U.S. patent application Ser. No.11/079,006 entitled “Systems and methods for posterior dynamicstabilization of the spine” filed on Mar. 10, 2005, now U.S. Pat. No.8,012,207, which is a continuation-in-part of U.S. patent applicationSer. No. 11/052,002 entitled “Systems and methods for posterior dynamicstabilization of the spine” filed on Feb. 4, 2005, now U.S. Pat. No.8,317,864, which is a continuation-in-part of U.S. patent applicationSer. No. 11/006,502 entitled “Systems and methods for posterior dynamicstabilization of the spine” filed on Dec. 6, 2004, now U.S. Pat. No.8,123,807, which is a continuation-in-part of U.S. patent applicationSer. No. 10/970,843 entitled “Systems and methods for posterior dynamicstabilization of the spine” filed on Oct. 20, 2004, now U.S. Pat. No.7,884,059 all of which are hereby incorporated by reference in theirentireties.

FIELD

The present invention generally relates to medical devices for thespine. In particular, the present invention relates to minimallyinvasive instruments for delivery of an implant between adjacent spinousprocesses of a patient's spine.

BACKGROUND

With spinal stenosis, the spinal canal narrows and pinches the spinalcord and nerves, causing pain in the back and legs. Typically, with age,a person's ligaments may thicken, intervertebral discs may deteriorateand facet joints may break down all contributing to the condition of thespine characterized by a narrowing of the spinal canal. Injury,heredity, arthritis, changes in blood flow and other causes may alsocontribute to spinal stenosis.

Doctors have been at the forefront with various treatments of the spineincluding medications, surgical techniques and implantable devices thatalleviate and substantially reduce debilitating pain associated with theback. In one surgical technique, a spacer is implanted between adjacentspinous processes of a patient's spine. The implanted spacer opens thespinal canal, maintains the desired distance between vertebral bodysegments, and as a result, avoids impingement of nerves and relievespain. For suitable candidates, an implantable interspinous spacer mayprovide significant benefits in terms of pain relief.

Any surgery is an ordeal. However, the type of device and how it isimplanted has an impact. For example, one consideration when performingsurgery to implant an interspinous spacer is the size of the incisionthat is required to allow introduction of the device. Small incisionsand minimally invasive techniques are generally preferred as they affectless tissue and result in speedier recovery times. As such, there is aneed for interspinous process spacers and instruments that deliver themthat work well with surgical techniques that are minimally invasive forthe patient. The present invention sets forth such an instrument.

SUMMARY

According to one aspect of the invention, an instrument is provided. Theinstrument includes a handle connected to a first assembly. The firstassembly comprises an outer shaft. An inner shaft is located inside theouter shaft and configured for relative translational motion withrespect to the outer shaft. A control is configured to effect therelative translational motion wherein the relative translational motioncauses one of the outer or inner shafts to move with respect to theother and thereby deflect at least one prong formed on one of the inneror outer shafts. Such deflection causes connection or engagement with ajuxtapositioned spacer. A driver having a distal portion configured toreversibly arrange the spacer between and including at least onedeployed configuration and at least one undeployed configuration.

According to another aspect of the invention, an instrument having alongitudinal axis and connectable to a spacer is provided. Theinstrument comprises a substantially radiolucent portion connected to asubstantially non-radiolucent portion. The substantially non-radiolucentportion has a radiographic projection on a plane perpendicular to thelongitudinal axis that is substantially coincident with a radiographicor non-radiographic projection of a connected undeployed spacer on saidplane.

According to another aspect of the invention, a method is disclosed. Themethod includes the step of connecting an interspinous spacer to adistal end of an instrument. The connected interspinous spacer isinserted into an interspinous space of a patient's spine with theinstrument. The interspinous spacer is arranged by the instrument intoat least one deployed configuration while the interspinous spacer isinserted in the interspinous space. The interspinous spacer isdisconnected from the instrument leaving the interspinous spacer locatedin the interspinous space.

According to another aspect of the invention, a method is disclosed. Themethod includes the step of inserting a distal end of an instrument intoan interspinous space of a patient's spine. The distal end of theinstrument is connected to an interspinous spacer implanted in theinterspinous space. The interspinous spacer is arranged with saidinstrument into at least one undeployed configuration while saidinstrument is inserted in the interspinous space and connected to theinterspinous spacer. The connected interspinous spacer is removed fromthe patient with the instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in conjunction with the accompanying drawings. It isemphasized that, according to common practice, the various features ofthe drawings are not to-scale. On the contrary, the dimensions of thevarious features are arbitrarily expanded or reduced for clarity.

FIG. 1 illustrates a perspective view of a spacer insertion instrumentwithout a driving tool according to the present invention.

FIG. 2 illustrates a side view of a spacer insertion instrument withouta driving tool according to the present invention.

FIG. 3 illustrates a front view of a spacer insertion instrument withouta driving tool according to the present invention.

FIG. 4 illustrates an end view of a spacer insertion instrument withouta driving tool according to the present invention.

FIG. 5 illustrates a top view of a spacer insertion instrument without adriving tool according to the present invention.

FIG. 6 illustrates a cross-sectional view of a spacer insertioninstrument without a driving tool according to the present invention.

FIG. 7 illustrates a cross-sectional view of an inner shaft of a spacerinsertion instrument according to the present invention.

FIG. 8 a illustrates a perspective view of an outer shaft of a spacerinsertion instrument according to the present invention.

FIG. 8 b illustrates a side view of an outer shaft of a spacer insertioninstrument according to the present invention.

FIG. 8 c illustrates a side view of an outer shaft of a spacer insertioninstrument according to the present invention.

FIG. 8 d illustrates a cross-sectional view of an outer shaft of aspacer insertion instrument according to the present invention.

FIG. 9 a illustrates a perspective view of a control of a spacerinsertion instrument according to the present invention.

FIG. 9 b illustrates a perspective view of a control of a spacerinsertion instrument according to the present invention.

FIG. 9 c illustrates a cross-sectional view of a control of a spacerinsertion instrument according to the present invention.

FIG. 10 a illustrates a perspective view of a proximal end cap of aspacer insertion instrument according to the present invention.

FIG. 10 b illustrates a perspective view of a proximal end cap of aspacer insertion instrument according to the present invention.

FIG. 11 illustrates a perspective view of a distal end cap of a spacerinsertion instrument according to the present invention.

FIG. 12 a illustrates a perspective view of a spacer in an undeployedconfiguration.

FIG. 12 b illustrates a perspective view of a spacer in a deployedconfiguration.

FIG. 13 a illustrates a perspective view of a spacer in an undeployedconfiguration.

FIG. 13 b illustrates a perspective view of a spacer in a deployedconfiguration.

FIG. 14 a illustrates a perspective view of a spacer in an undeployedconfiguration.

FIG. 14 b illustrates a perspective view of a spacer in a deployedconfiguration.

FIG. 15 a illustrates a perspective view of a driving tool according tothe present invention.

FIG. 15 b illustrates a side view of a driving tool according to thepresent invention.

FIG. 15 c illustrates a partial perspective view of a driving toolaccording to the present invention.

FIG. 16 illustrates a perspective view of a spacer insertion instrumentand driving tool connected to a spacer in a deployed configurationaccording to the present invention.

FIG. 17 illustrates a cross-sectional view of a spacer insertioninstrument and driving tool connected to a spacer in an undeployedconfiguration according to the present invention.

FIG. 18 illustrates a partial cross-sectional view of a spacer insertioninstrument and driving tool connected to a spacer in an undeployedconfiguration according to the present invention.

FIG. 19 illustrates a cross-sectional view of a spacer insertioninstrument and driving tool connected to a spacer in a deployedconfiguration according to the present invention.

FIG. 20 illustrates a partial cross-sectional view of a spacer insertioninstrument and driving tool connected to a spacer in a deployedconfiguration according to the present invention.

DETAILED DESCRIPTION

Turning to FIGS. 1-6, there is shown a spacer insertion instrument 10according to the present invention. The spacer insertion instrument 10includes a first assembly 12 connected to a handle assembly 14 andretained by a distal end cap 16 and a proximal end cap 18. Theinstrument 10 also includes a driving tool 66 that is removablyinsertable into the central passageway of the instrument 10. FIGS. 15 a,15 b and 15 c illustrate the driving tool 66 and FIG. 16 shows theinstrument 10 with the driving tool 66 inserted.

Still referencing FIGS. 1-6, the first assembly 12 of the insertioninstrument 10 is configured to releasably clamp to a body of aninterspinous process implant to be delivered into or removed from apatient using the instrument 10. The first assembly 12 includes an innershaft 20, an outer shaft 22 and a control 24. The inner shaft 20 isconnected to the handle assembly 14 and the outer shaft 22 is passedover the inner shaft 20 and allowed to translate with respect thereto bymeans of a control 24 that is threadingly engaged with the outer shaft22. With rotation of the control 24 in either direction, the outer shaft22 translates with respect to the stationary inner shaft 20. In anothervariation of the invention, the outer shaft 22 is connected to handleassembly 14 and the inner shaft 20 is threadingly engaged with thecontrol 24 such that rotation of the control 24 moves the inner shaft 20with respect to the outer shaft 22. Although rotation of the control 24is used in one variation, other variations are within the scope of thepresent invention such as, for example, translation of the control 24 ormovement of the outer shaft 22 relative to the inner shaft 20.

Turning now to FIG. 7, there is shown an inner shaft 20 according to thepresent invention. As seen in the drawings, the inner shaft 20 issubstantially cylindrical in shape having a central bore 26 extendingfrom end to end. The distal end of the inner shaft 20 includes a pair ofprongs 28 with each prong being substantially oppositely located fromeach other. The finger-like prongs 28 are formed by openings 30extending proximally from the distal end. The fingers are flexible and,when in a normal position, splay slightly outwardly from thelongitudinal axis as shown in FIG. 7. The prongs 28 are configured toconnect with a spacer 32 of the like shown in FIGS. 12-14 or othersimilar spacers. In particular, the prongs 28 include extensions 34 thatextend inwardly toward the longitudinal axis in a hook-like fashion.These extensions 34 are configured to be inserted into prong-receivingportions 36 (see FIGS. 12-14) on the spacer 32 and securely clampthereto. The prongs 28 also include conforming surfaces 38 configured toconform to the spacer 32 in a manner best suited for secure attachmentthereto. The proximal end of the inner shaft 20 includes a proximalportion 40 having a larger cross section and configured for insertioninto a conformingly shaped recess in the handle assembly 14.

Turning now to FIGS. 8 a-8 d, there is shown the outer shaft 22 of thefirst assembly 12. As seen in the drawings, the outer shaft 22 issubstantially cylindrical in shape having a central bore 42 extendingfrom end to end. The outer shaft 22 is sized such that the inner shaft20 fits inside the outer shaft 22. The distal end includes a pair offlattened portions 44 located substantially opposite from each other.There is a middle portion 46 having a larger cross-section and athreaded proximal portion 48. The threaded proximal portion 48 isconfigured for threaded connection with the control 24. In onevariation, the middle portion 46 includes features such as an octagonalshape as seen in FIG. 16 that serve to align the instrument 10 wheninserted into a cannula positioned to an interspinous space of apatient. The features on the middle portion 46 are aligned with similarcomplementary features on a cannula so that insertion of the instrumentinto the cannula is limited by the alignment of the features with theresult being proper orientation of the instrument relative to thecannula and in turn relative to the patient. The outer shaft 22 includesat least one aperture formed in the sidewall of the shaft to provideaccess to the inner shaft and the interior of the shaft construct forcleaning purposes.

Turning now to FIGS. 9 a-9 c, there is shown the control 24 of the firstassembly 12. The control 24 includes a user interface such as a fingerportion or grip 50. In the variation shown in FIGS. 9 a-9 c, the userinterface 50 is an outer circular or disk shaped portion for easilyeffecting rotation of the control 24 with a thumb or index finger. Thecontrol 24 also includes a connecting portion 52 that connects thecontrol 24 to effect relative translation of the inner shaft 20 withrespect to the outer shaft 22. In particular, in the variation shown inthe drawings, the connecting portion 52 is a cylindrical portionconnected to the user interface 50. The cylindrical portion has athreaded inner surface for engaging the threaded proximal portion 48 ofthe outer shaft 22 wherein the outer shaft 22 is received inside athreaded bore 54 of the connecting portion 52.

Turning now to FIGS. 10 a and 10 b, there is shown the proximal end cap18 of the present invention. The end cap 18 is configured to cap theproximal end of the handle assembly 14. The handle assembly 14, if madeof multiple parts, is held together, in part, by the end cap 18,capturing at least a portion of the first assembly 12 therein. The endcap 18 includes a central bore 56 providing a passage through theinstrument 10 end to end. Also, apertures 58 are formed in the end cap18 for receiving fasteners (not shown) therein for attachment to thehandle assembly 14.

Turning now to FIG. 11, there is shown the distal end cap 16 of thepresent invention. The end cap 16 is configured to cap the distal end ofthe handle assembly 14. The handle assembly 14, if made of multipleparts, is held together, in part, by the distal end cap 16, capturing atleast a portion of the first assembly 12 therein. The distal end cap 16includes a central bore 60 sized to receive the outer shaft 22 therein.Also, apertures 62 are formed in the end cap 16 for receiving fasteners(not shown) therein for attachment to the handle assembly 14. In onevariation, the distal end cap 16 has a directional indicator 64 in theshape of an arrow indicating, for example, a direction information suchas “cephalad” as shown in FIG. 3 to help the surgeon to easily orientatethe instrument 10.

The assembly of the spacer insertion instrument 10 will now bedescribed. With particular reference back to FIG. 6, the control 24 isthreaded onto the threaded proximal portion 48 of the outer shaft 22.The prongs 28 of the inner shaft 20 are compressed together slightly andthe inner shaft 20 is inserted into the outer shaft 22. The firstassembly 12 is then placed inside first assembly receiving portions ofthe handle assembly 14 and if more than one piece comprises the handleassembly 14 as, for example, in a clam shell construction, the handleassembly 14 is joined and secured together by the distal and proximalend caps 14, 16 fastened to the handle assembly 14. Additional fasteningelements such as fasteners, screws, glue and the like may also beadditionally or alternatively employed to capture at least a portion ofand secure the first assembly 12 inside the handle assembly 14. With theinstrument 10 assembled, there is a central passageway 67 clearlyvisible in the cross-sectional view of the instrument 10 shown in FIG.6. The central passageway 67 extends from one end to the other end ofthe instrument 10. Through this central passageway 67, the driving tool66 is removably inserted to deploy or undeploy the interspinous spacer.FIG. 16 illustrates a driving tool 66 inserted into the instrument 10and engaged with a spacer 32 in a deployed configuration.

Jumping now to FIGS. 15 a, 15 b and 15 c, there is shown a driving tool66 according to the present invention. The driving tool 66 includes ahandle 74 at the proximal end and a spacer engaging bit 76 at the distalend. The handle 74 and bit 76 are interconnected by a middle shaftportion 78. The driving tool 66 is configured and sized to be insertedinto the central passageway 67 of the instrument 10 such that the bit 76at the distal end operatively connects with a spacer loaded and lockedinto the prongs 28 of the instrument 10. The distal bit 78 includesfeatures 80 for engaging with the operative portion of the spacer 32 inorder to effect deployment or undeployment of the spacer 32. A drivingtool 66 may have a different distal bit 76 in order to mate with acomplementarily different member on the spacer. For example, the drivingtool 66 shown in FIG. 15 includes features 80 comprising two oppositelylocated projections which are configured to mate with complementaryfeatures on the spacer. In another variation of the driving tool 66, thedistal bit 66 may simply be a hexagonally shaped or other polygonalshaped member that fits inside a complementary member or hex socket onthe spacer. In essence, different driving tools 66 having differentdistal bits 76 may be employed depending on the design of the spacerwith which it is to be used. The instrument is advantageously configuredsuch that torque placed on the handle 74 of the driving tool 66 whilearranging the spacer is countered by grasping the handle assembly 14 toprovide a counter-torque preventing twisting or misalignment of theinstrument relative to the implantation site.

The spacer insertion instrument 10 functions to engage with, insert anddeploy an interspinous spacer. Illustrative examples of interspinousspacers that are compatible with the insertion instrument are describedin applicant's co-pending U.S. patent application Ser. No. 12/217,662entitled “Interspinous spacer” filed on Jul. 8, 2008 incorporated hereinby reference in its entirety, U.S. patent application Ser. No.12/220,427 entitled “Interspinous spacer” filed on Jul. 24, 2008incorporated herein by reference in its entirety, U.S. patentapplication Ser. No. 12/205,511 entitled “Interspinous spacer” filed onSep. 5, 2008 incorporated herein by reference in its entirety, and U.S.Provisional Patent Application Ser. No. 61/011,199 entitled“Interspinous spacer” filed on Jan. 15, 2008 incorporated herein byreference in its entirety. Examples of such interspinous spacers 32 areshown in FIGS. 12-14 wherein like reference numerals are used todescribe like parts. In general, each spacer 32 includes a body portion68 with at least one prong receiving portion 36 for connecting with theinstrument 10, at least one wing 70 rotatably connected to the bodyportion 68 and an actuator shaft 72 housed in the body portion 68 andconfigured to arrange the at least one wing 70 from at least oneundeployed configuration (see FIGS. 12 a, 13 a and 14 a) to at least onedeployed configuration (see FIGS. 12 b, 13 b and 14 b) and vice versa.The at least one wing serves as a body portion 68 stabilizer withrespect to at least one adjacent spinous process of a patient's spineand is configured in one variation to cradle an adjacent spinous processon both sides and in another variation forming a seat for an adjacentspinous process.

The spacer insertion instrument 10 utilizes a working channel accessinga patient's spine that is preferably created by the use of one or moretools such as a target needle, K-wire, dilators, mounting bracket,cannula, stabilizing arm, interspinous knife, interspinous reamer, andinterspinous gage, all described in applicant's co-pending U.S. patentapplication Ser. No. 11/582,874 entitled “Minimally invasive tooling fordelivery of interspinous spacer” filed on Oct. 18, 2006, incorporatedherein by reference in its entirety. The spacer insertion instrument 10is typically inserted through a cannula having a distal end positionedat the interspinous process space in a minimally invasive, percutaneous,mini-open or open surgical procedure. In some procedures, a cannula isnot employed to deliver the instrument 10 and spacer 32 to theinterspinous space.

In use, a spacer 32 is placed in juxtaposition to the distal end of theinsertion instrument 10 such that the prongs 28 of the instrument 10 areadjacent to the prong receiving portions 36 on the spacer 32. Thecontrol 24 is then activated to clamp the prongs 28 of the inner shaft20 onto the spacer 32. In particular, the control 24 is rotated in onedirection which advances the outer shaft 22 over the inner shaft 20 tothereby inwardly deflect the outwardly extending prongs 28 at the distalend of the inner shaft 20. This inward deflection allows the prongs 28to engage the spacer body and, in particular, allows the prongextensions 34 to be inserted into the prong receiving portions 36 andwith further rotation of the control 24 to lock the instrument 10securely onto the spacer 32. Reverse rotation of the control 24translates the outer shaft 22 proximally to expose the prongs 28allowing them to deflect outwardly to their pre-stressed normal positionand thereby release the spacer 32 from the insertion instrument 10.

If a cannula is employed in the operative site, the insertion instrument10 with the attached spacer 32 in an undeployed configuration is sizedto fit through a cannula and is passed through the cannula to theinterspinous process space. Once in position inside the patient, adriving tool 66 is inserted into the proximal opening of the centralpassageway 67 of the instrument and passed until the distal spacerengaging bit 76 of the driving tool 66 connects with the spacer 32. Theconnection of the driver 66 to the spacer is signaled via tactilefeedback of the bit engaging the spacer. Depending on the spacer design,the connection of the driving tool 66 with the spacer 32, in particularthe engaging features 80, 82, will be different. In general, however,the driving tool 66 connects to the spacer 32 such that movement, suchas rotation and/or translation, of the driving tool 66 effectsdeployment of the at least one wing 70 of the spacer 32. Such deploymentof the wings is continuous with the rotation and/or translation of thedriving tool. As a result, the deployment may be stopped by stoppingsuch rotation making the deployment incremental. Such incrementaldeployment allows the surgeon to observe incremental deployment progressvia fluoroscopic observation inbetween rotations to help properlyposition the instrument. Hence, the spacer and instrument combinationprovides incremental and continuos deployment unlike otherspacer/instrument combinations that only have one deployed configurationand one undeployed configuration with no intermediate configurations ormeans provided by the instrument to gradually arrange the spacertherebetween. In particular and with respect to the spacer embodimentsshown in FIGS. 12-14, movement, such as rotation and/or translation, ofthe driving tool effects translation of the actuator shaft 72 which inturn is connected to the at least one wing 70 causing it to deploy intoan expanded configuration.

With particular reference now to FIGS. 12 a and 12 b, the driving tool66 that is configured to connect with the spacer shown in FIGS. 12 a and12 b will have a spacer engaging bit 76 that has a hexagonally shapedmember that is sized to fit inside the complementarily hexagonallyshaped interior 84 of the actuator shaft 72. With the instrument 10operatively positioned inside the patient and with the driving toolengaged to the actuator shaft 72, rotation of the driving tool 66distally advances the actuator shaft 72 to deploy the wings 70 into theconfiguration shown in FIG. 12 b. Of course, any polygonal or othershape may be employed. Reverse rotation of the driving tool 66 willproximally retract the actuator shaft 72 to undeploy the wings 70.

With particular reference now to FIGS. 13 a, 13 b and FIGS. 17-20, thedriving tool 66 that is configured to connect with the spacer 32 shownin FIGS. 13 a and 13 b will have a configuration of the like shown inFIGS. 15 a, 15 b and 15 c wherein the spacer engaging bit 76 includestwo projecting features 80. The two projecting features 80 engagecomplementary features 88 on a spindle 86 located inside the bodyportion 68 of the spacer 32 as shown in FIG. 18. Once engaged to thespindle 86 (see FIG. 17), rotation of the driving tool 66 rotates thespindle 86 which in turn advances the actuator shaft 72 to deploy thewings 70 into the configuration shown in FIGS. 13 b, 19 and 20. As canbe seen in these figures, when in the deployed configuration, theactuator shaft 72 is distally translated with rotation of the drivingtool. Reverse rotation of the driving tool 66 will turn the spindle 86in an opposite direction and proximally translate the actuator shaft 72to undeploy the wings 70 into position shown in FIGS. 13 a and 17.

With particular reference now to FIGS. 14 a and 14 b, the driving tool66 that is configured to connect with the spacer shown in FIGS. 14 a and14 b will have a spacer engaging bit 76 that has a hexagonally shapedmember that is sized to fit inside the complementarily hexagonallyshaped interior 84 of the actuator shaft 72. With the instrument 10operatively positioned inside the patient and with the driving toolengaged to the actuator shaft 72, rotation of the driving tool 66proximally advances the actuator shaft 72 to deploy the wings 70 intothe configuration shown in FIG. 14 b. Of course, any polygonal or othershape may be employed and reverse rotation of the driving tool 66 willdistally advance the actuator shaft 72 to undeploy the wings 70.

For all of the spacer embodiments described above with which theinsertion instrument 10 may be used, the driving tool 66 is activated byrotation. However, the driving tool may be activated by translation todeploy a spacer of the like described in applicant's co-pending U.S.patent application Ser. No. 11/314,712 entitled “Systems and methods forposterior dynamic stabilization of the spine” filed on Dec. 20, 2005 andU.S. patent application Ser. No. 11/593,995 entitled “Systems andmethods for posterior dynamic stabilization of the spine” filed on Nov.7, 2006, both of which are incorporated herein by reference in theirentireties. Other examples of spacers with which the insertioninstrument or modified version thereof may be employed are disclosed inU.S. patent application Ser. No. 11/079,006 entitled “Systems andmethods for posterior dynamic stabilization of the spine” filed on Mar.10, 2005 and U.S. patent application Ser. No. 11/190,496 entitled“Systems and methods for posterior dynamic stabilization of the spine”filed on Jul. 26, 2005 both of which are incorporated herein byreference in their entireties.

Furthermore, the driving tool may be activated by rotation andtranslation of the driving tool to deploy the spacers of the like shownin FIGS. 12 a, 12 b, 14 a and 14 b. Activation of the driving tool todeploy the spacer that involves translation of the driving tooladvantageously provides the user with a degree of deploymentinformation. This feature is particularly important because positioningand deployment of the instrument and spacer may result in the wings 70abutting tissue, bone or other obstructions within the patient thatwould signal to the user to either reposition the instrument and spaceror clear any obstructions. An example of a degree of deploymentinformation feature includes translation of the driving tool. Forexample, if translation of the driving tool is less than a specificmarker or distance, the user will know that the spacer is not fullydeployed or that there is some obstruction and further movement of thedriving tool, repositioning or removal of an obstruction is required forfull deployment. In one variation, the handle 74 of the driving tool 66rests a certain distance from the proximal end of the handle assembly 14and with rotation, the driving tool 66 advances until the handle 74 ofthe driving tool contacts the proximal end of the handle assembly 14. Inanother variation, the middle shaft 78 of the driving tool 66 includesmarkings that indicate to the user the distance that the driving toolhas moved distally or proximally to provide a degree of deploymentinformation.

Of course, the spacer may have more than one deployed configuration aswell as more than one undeployed configuration as the system permitsvarying degrees of deployment according to surgeon preference. Also, thedeployment is reversible such that along any stage of deployment thedriving tool can change the direction of translation of the actuatorshaft of the spacer and hence, reverse deployment of the wings. Thedegree of translation of the actuator shaft and hence deployment of thespacer is variable. This variability advantageously permits the spacerto have multiple deployment configurations. Also, at intermediate levelsof deployment, the spacer in conjunction with the instrument serves as acustomized distractor. Once the spacer is in position and in the desireddeployed configuration between adjacent interspinous processes of apatient's spine, the control 24 is activated in an opposite direction torelease the prongs 28 and disconnect the spacer from the instrument. Theinsertion instrument is then removed from the patient leaving the spacerin place. With the spacer in place, the wings cradle the spinousprocesses. If two wings are employed, they cradle both of the adjacentspinous processes for a given interspinous process space. The spacerbody alone, the wings alone, or the body in conjunction with one or moreof the wings space apart the adjacent spinous processes and as a result,the implanted spacer opens the spinal canal, maintains the desireddistance between vertebral body segments, and as a result, avoidsimpingement of nerves and relieves pain.

The insertion instrument can also be used to remove a spacer from thepatient or to adjust its position following deployment. In such a case,the insertion instrument is inserted into a cannula, if one is employed,the cannula being accessed to an interspinous process space of a patientand positioned proximate to the spacer located in the interspinousspace. Then the control 24 is activated to connect the instrument to thebody with tactile feedback of the connection provided by the instrumentconfiguration. A driving tool 66 is also inserted and connected to thespacer to undeploy the spacer wings. With the wings in at least oneundeployed configuration, the spacer can then be removed or repositionedand redeployed.

In typical applications, the insertion instrument includes a variety ofmarkings, for example, to indicate various status conditions of the tooland the associate interspinous spacer. In an alternative arrangement,the markings are selected as conventional visible markings or may beradio-opaque. The insertion instrument may also be optionally arrangedwith one or more markers selected, for example, from ultrasonic,magnetic markers or other marker types to advantageously avoid the needfor fluoroscopy.

The disclosed devices or any of their components can be made of anybiologically adaptable or compatible materials including PEEK, PEK,PAEK, PEKEKK or other polyetherketones. Materials considered acceptablefor biological implantation are well known and include, but are notlimited to, stainless steel, titanium, tantalum, combination metallicalloys, various plastics, polymers, resins, ceramics, biologicallyabsorbable materials and the like. In one variation, the instrumentincludes a substantially radiolucent portion connected to asubstantially non-radiolucent portion. For example, the non-radiolucentportion may be comprised of at least a portion of the first assembly 12and the radiolucent portion may be comprised of at least a portion ofthe handle assembly 14. The substantially non-radiolucent portion is asubstantial portion of radiolucent material that is exclusive of smallfasteners or other features found scattered in a radiographicprojection. The substantially non-radiolucent portion has a radiographicprojection on a plane perpendicular to the longitudinal axis that issubstantially coincident with a radiographic projection of a connectedspacer on said plane when in at least one undeployed configuration. Thisfeature is advantageous for minimally invasive surgical procedureswherein fluoroscopic observations assist the surgeon in correctplacement of an implant while providing the patient with less tissueintrusion that would otherwise be the case in larger incisions or opensurgical procedures because the substantial radiolucent portions of theinstrument do not obstruct fluoroscopic imaging of the implantation sitefor positioning and guiding the implant. This is the case when theinstrument is connected to a spacer, inserted posteriorly withradiographic projections taken along a substantially anterior-posteriorview of the patient's body. This is also the case when the instrument isused to deploy the spacer into at least one deployed configurationwherein the radiographic or non-radiographic projection of the spacer ona plane perpendicular to the longitudinal axis is substantiallycoincident with a radiographic projection of a substantial portion ofthe instrument made of substantially non-radiolucent material. However,the instrument and spacer are configured such that when the wings arearranged in at least one deployed configuration, the projection of thedeployed wings on said plane extend beyond the perimeter of theprojection of non-radiolucent portions such that the wings and theirposition can be observed under fluoroscopic observation, thereby, thephysician can see the deployment of the wings without obstruction fromthe rest of the instrument and then undeploy and redeploy the wings asnecessary or reposition the instrument for proper placement of thespacer and improve implantation according to patient anatomy. Therefore,this instrument and spacer system greatly improves ease of implantationfor the surgeon, reduces surgery time, increases patient recovery andsignificantly improves upon minimally invasive techniques. In onevariation, the non-radiolucent portion substantially comprises a spacerconnecting shaft. In one variation, non-radiolucent portions include theshaft 78 of the driving tool 66 and radiolucent portion include thehandle 74 of the driver 66.

The preceding merely illustrates the principles of the invention. Itwill be appreciated that those skilled in the art will be able to devisevarious arrangements which, although not explicitly described or shownherein, embody the principles of the invention and are included withinits spirit and scope. Furthermore, all examples and conditional languagerecited herein are principally intended to aid the reader inunderstanding the principles of the invention and the conceptscontributed by the inventors to furthering the art, and are to beconstrued as being without limitation to such specifically recitedexamples and conditions. Moreover, all statements herein recitingprinciples, aspects, and embodiments of the invention as well asspecific examples thereof, are intended to encompass both structural andfunctional equivalents thereof. Additionally, it is intended that suchequivalents include both currently known equivalents and equivalentsdeveloped in the future, i.e., any elements developed that perform thesame function, regardless of structure. The scope of the presentinvention, therefore, is not intended to be limited to the exemplaryembodiments shown and described herein. Rather, the scope and spirit ofpresent invention is embodied by the appended claims.

We claim:
 1. An instrument for inserting and deploying an interspinousspacer having a body with at least one prong receiving portion and awing rotatably connected to the body portion, wherein the wing isconfigured to cradle an adjacent spinous process, the instrumentcomprising: a handle, a first assembly connected to the handle, thefirst assembly comprising an outer shaft, an inner shaft located insidethe outer shaft, at least one prong at a distal portion of one of theouter or inner shafts, and a control configured to move one of the outeror inner shafts with respect to the other and thereby deflect the pronginto engagement with the prong receiving portion of the body of theinterspinous spacer, wherein the body of the interspinous spacer isprevented from rotating with respect to the prong when the prong engagesthe prong receiving portion; and a driver having a distal portionconfigured to arrange the interspinous spacer, and wherein the driver isaxially displaceable relative to the first assembly independent of (a)rotation of the driver about an axis of rotation defined by the firstassembly such that the driver moves relative to the prong to deploy theinterspinous spacer and (b) operation of the control.
 2. The instrumentof claim 1 wherein the driver is configured for removable insertion at aproximal end into a passageway of the instrument.
 3. The instrument ofclaim 1 wherein the driver is configured to deploy or undeploy thespacer between and including at least one undeployed configuration andat least one deployed configuration.
 4. The instrument of claim 3wherein the at least one deployed configuration is characterized by atleast one wing of said spacer cradling both sides of an interspinousprocess of a patient's spine when said spacer is implanted into aninterspinous process space.
 5. The instrument of claim 1 wherein thedriver has a distal spacer engaging portion; said distal spacer engagingportion configured to engage that a part of the spacer requiringactivation to arrange the spacer.
 6. The instrument of claim 1 whereinthe outer shaft includes at least one sidewall opening.
 7. Theinstrument of claim 1 further including counter torque means connectedto the handle assembly for countering torque from the driver.
 8. Theinstrument of claim 1, wherein the instrument has a longitudinal axis, asubstantially radiolucent portion, and a substantially non-radiolucentportion connected to the substantially radiolucent portion, wherein thesubstantially non-radiolucent portion has a radiographic projection on aplane perpendicular to the longitudinal axis, and wherein the spacer hasa projection that is substantially coincident with the substantiallyradiographic projection.
 9. The instrument of claim 8 wherein thesubstantially radiographic projection of the substantiallynon-radiolucent portion on said plane is substantially coincident withthe projection of the spacer in an undeployed configuration andconnected to the instrument.
 10. The instrument of claim 8 wherein thesubstantially radiographic projection of the substantiallynon-radiolucent portion on said plane is substantially coincident withthe projection of the spacer in a deployed configuration and connectedto the instrument except for the projection of the spacer.
 11. Theinstrument of claim 8 wherein the substantially non-radiolucent portioncomprises a spacer connecting shaft.
 12. The instrument of claim 11wherein the radiolucent portion comprises a handle assembly.
 13. Theinstrument of claim 1 wherein the prong is configured to move inwardlyinto the prong receiving portion when the outer shaft and the innershaft move relative to one another.
 14. The instrument of claim 1wherein the prong is configured to move outwardly away from the body ofthe interspinous spacer when the outer shaft and the inner shaft moverelative to one another.
 15. The instrument of claim 1 wherein the prongincludes a prong extension that is insertable into the prong receivingportion as the prong is deflected inwardly towards a longitudinal axisof the instrument.
 16. The instrument of claim 1 wherein the control isconfigured to rotate in a first direction to move the outer shafttowards the prong to move the prong towards an inward position, whereinthe control is configured to rotate in a second direction to move theouter shaft away from the prong to allow the prong to move outwardlyaway from the inward position, and wherein the first direction isdifferent from the second direction.
 17. An instrument for inserting anddeploying an interspinous spacer having a body with at least one prongreceiving portion, the instrument comprising: a handle; a first assemblycoupleable to the handle, the first assembly comprising an outer shaft,an inner shaft, at least one prong, and a control configured to move theouter shaft relative to the inner shaft to move the prong inwardlytowards a longitudinal axis of the instrument such that the prong isreceived by the prong receiving portion of the body; and a driverconfigured to deploy the interspinous spacer, wherein the driver isconfigured to rotate relative to the prong independent of operation ofthe control, and wherein the driver is axially movable along the firstassembly independent of rotation of the driver relative to the firstassembly.
 18. The instrument of claim 17 wherein the prong is configuredto move inwardly into the prong receiving portion when the outer shaftmoves relative to the inner shaft.
 19. The instrument of claim 17wherein the prong includes a prong extension that is insertable into theprong receiving portion to clamp onto the interspinous spacer.
 20. Theinstrument of claim 17 wherein the prong is movable from a pre-stressedposition to a clamping position, the prong in the pre-stressed positionflares outwardly, and the prong in the clamping position is configuredto retain the interspinous spacer.
 21. An instrument for inserting anddeploying an interspinous spacer having a body with at least one prongreceiving portion, the instrument comprising: a handle; a first assemblycoupleable to the handle, the first assembly comprising an outer shaft,an inner shaft, at least one prong, and a control configured to move theouter shaft relative to the inner shaft to move the prong inwardlytowards a longitudinal axis of the instrument such that the prong isreceived by the prong receiving portion of the; and a driver configuredto deploy the interspinous spacer, wherein the driver is positioned inthe inner shaft and has a hexagonal shaped member positioned to engage acomplementary hexagonal shaped recess of the interspinous spacer.